Setting Up FTP Using VSFTPD

Vsftpd (Very Secure FTP Daemon) is an FTP server for UNIX-like systems, including CentOS / RHEL / Fedora and other Linux distributions.

Install VSFTPD FTP Server

Install the vsftpd package via yum or apt-get command depending on what OS are you using:

[root@burnzserver]# yum install vsftpd

VSFTPD Defaults

1. Default Port: TCP/UDP – 21 and 20
2. The main configuration file: /etc/vsftpd/vsftpd.conf
3. Users that are allowed to login via ftp: /etc/vsftpd/ftpusers

Configure Vsftpd Server

Open the configuration file:

[root@burnzserver]# nano /etc/vsftpd/vsftpd.conf

Turn off standard ftpd xferlog log format:

xferlog_std_format=NO

Turn on verbose vsftpd log format. The default vsftpd log file is /var/log/vsftpd.log:

log_ftp_protocol=YES

Above to directives will enable logging of all FTP transactions. Lock down users to their home directories:

chroot_local_user=YES

Create warning banners for all FTP users:

banner_file=/etc/vsftpd/issue

Create /etc/vsftpd/issue file with a message compliant with the local site policy or a legal disclaimer:

NOTICE TO USERS
Use of this system constitutes consent to security monitoring and testing.
All activity is logged with your host name and IP address.

Turn On Vsftpd Service
Turn on vsftpd on boot:

[root@burnzserver]# chkconfig vsftpd on

Start the service

[root@burnzserver]# service vsftpd start
[root@burnzserver]# netstat -tupln | grep :21

Configure Iptables To Protect The FTP Server
Open file /etc/sysconfig/iptables, enter:

[root@burnzserver]# nano /etc/sysconfig/iptables

Add the following lines, ensuring that they appear before the final LOG and DROP lines for the RH-Firewall-1-INPUT:

-A RH-Firewall-1-INPUT -m state --state NEW -p tcp --dport 21 -j ACCEPT

Open file /etc/sysconfig/iptables-config, enter:

[root@burnzserver]# nano /etc/sysconfig/iptables-config

Ensure that the space-separated list of modules contains the FTP connection tracking module:

IPTABLES_MODULES="ip_conntrack_ftp"

Save and close the file. Restart firewall:

[root@burnzserver]# service iptables restart

Tip: Restrict Access to Anonymous User Only
Edit the vsftpd configuration file /etc/vsftpd/vsftpd.conf and add the following:

local_enable=NO

Tip: Disable FTP Uploads
Edit the vsftpd configuration file /etc/vsftpd/vsftpd.conf and add the following:

write_enable=NO

Create An FTP User Account

Since your FTP server is up and running. We need to add additional users to FTP server so that they can login into account to upload / download files. Lets say you wanted to add burnz as user the following step should be followed:
1. Create a username burnz and the home directory for your FTP

 
[root@burnzserver]# useradd -d /path/to/ftp/directory -s /sbin/nologin burnz

2. Create a password for the user burnz

[root@burnzserver]# passwd burnz

3. Check that the user has been added on the server users and to what directory

[root@burnzserver]# cat /etc/passwd

4. Make sure the settings of your vsftp.conf is correct.
5. Go to the vsftpd directory

[root@burnzserver]# cd /etc/vsftpd/

6. Edit the vsftpd.conf

[root@burnzserver]# nano vsftpd.conf

It should have the same config as this:

# Example config file /etc/vsftpd/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=NO
#
# Uncomment this to allow local users to log in.
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES
#
# The target log file can be vsftpd_log_file or xferlog_file.
# This depends on setting xferlog_std_format parameter
xferlog_enable=YES
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=NO
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# The name of log file when xferlog_enable=YES and xferlog_std_format=YES
# WARNING - changing this filename affects /etc/logrotate.d/vsftpd.log
#xferlog_file=/var/log/xferlog
#
# Switches between logging into vsftpd_log_file and xferlog_file files.
# NO writes to vsftpd_log_file, YES to xferlog_file
xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that on some FTP servers, ASCII support allows a denial of service
# attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
# predicted this attack and has always been safe, reporting the size of the
# raw file.
# ASCII mangling is a horrible feature of the protocol.
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
#ftpd_banner=Welcome to blah FTP service.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd/banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
chroot_list_enable=YES
# (default follows)
chroot_list_file=/etc/vsftpd/chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
listen=YES
#
# This directive enables listening on IPv6 sockets. To listen on IPv4 and IPv6
# sockets, you must run two copies of vsftpd whith two configuration files.
# Make sure, that one of the listen options is commented !!
#listen_ipv6=YES
pasv_promiscuous=YES
pasv_enable=YES
chroot_local_user=NO
pam_service_name=vsftpd
userlist_enable=YES

5. Create a chroot list file under the vsftpd directory

 
[root@burnzserver]# nano /etc/vsftpd/chroot_list

6. Add this line and save

burnz

7. Restart vsftpd

 
[root@burnzserver]# /etc/init.d/vsftpd restart

It should be good.